Electrolytic device



June 14, 1938. N. SCHNOLL ELECTROLYTIC DEVICE Filed Feb. 20, 1935 s Sheets-Sheet 1 IN V EN TOR.

A TTORNEYS.

June 14, 1938. N. SCHNOLL ELECTROLYTIC DEVICE Filed Feb. 20, 1935 5 Sheets-Sheet 2 NATHAN sczmo LL W4 A TTORNEYS.

June 14, 1938. SCHNQLL 2,120,815

ELEC TROLYTI C DEVI CE Filed Feb. 20, 1935 3 Sheets-Sheet 3 NA THAN SCHNOLL INVENTOR. X?

% 'ATTORNEY.

Patented June 14, 1938 UNITED STATES ELECTROLYTIC DEVICE Nathan Schnoll, New York, N. Y., assignor to Solar Manufacturing Corporation, a corporation of New York Application February 20, 1935, Serial No. 7,341

3 Claims.

This invention relates to electrolytic condensers, rectifiers or similar electrolytic devices, comprising a film-forming anode of aluminum, tantalum or other metals, adapted to form a film .of unidirectional current-conducting quality under electrolytic action, and a cathode, usually in the shape of the outer container, which does not exhibit film formation, or at least, not to a marked or deleterious degree. This container may be made of. copper or nickel, but in the majority of cases it is likewise made of aluminum as this metal can be easier subjected to mechanical operations, drawing out in tubular form, spinning, beading or extruding, etc., and is also much lighter and cheaper than the aforementioned metals. Its shortcomings as a film-forming material can be overcome in different ways, by plating with chromium, treating with acids, etc., yet the present invention is not concerned with the cathode as such, but with certain improvements in the installation of the anode in reference to the cathode.

It is assumed in the present case that generally, but not necessarily, this cathode is formed by a I tubular aluminum container which is contracted at the. bottom into a rather substantial neck, threaded on the outside, so that when it is inserted into a circular aperture of a platform or chassis, the lower protruding end may be secured and clamped tight by a nut. However, the application of this invention is not limited to this special form of a cathode container, as will be shown in the course of the description. The lid of the container is generally formed by a separate piece, securely clamped or otherwise fastened onto the top rim of the container.

The anode or that member of the condenser device which is intended to exhibit film-forming qualities, is suspended or otherwise mounted within the container in such a way that it is carefully spaced on all sides from the container surface, so that no conductive contact with the latter may occur which of course would shortcircuit the condenser or rectifier. Aside from this general and common condition the anode may present the most various forms,-it may consist of a single plate or a multiplicity of plates. In many cases it is a strip of aluminum sheet metal fastened to and spirally wound around a stiff rod of the same metal, or a ribbon may be folded many times upon itself, as illustrated in oneof the accompanying figures. But in all these cases the anode must be connected to an outer terminal which may either be located on top 'of the condenser or, preferredly, on the bottom, below the chassis. This, to my knowledge, has been always done, up to the present, by extending the anode through an aperture in the container, forming the cathode, either through the lid or through the bottom neck, carefully insulating the place where the anode enters the container.

This construction involves the drawback that at one place or another the aluminum, on which the film is formed, passes from a liquid medium, the electrolytic solution, into a denser or less dense medium,-gaseous, when the anode hanger or rod is brought above the surface of the electrolyte through the upper lid, and solid, if the anode support in presence of. the electrolyte is carried through the bottom or the side. Now experience has shown that, in spite of many precautions, these z ones or spots of transition are especially vulnerable to corrosive influences, and one of the general and main objects of this invention is to avoid or at least minimize these drawbacks.

I am aware that in some of the constructions, presented by the former art, the first kind of these transitions,-the passing of the anode through the gaseous atmosphere above the electrolyte-is avoided by completely submerging the anode. This, however, does not protect the transit of the anode through the bottom or through the packing of the bottom neck of the container.

In view of. these drawbacks, outlined above- It is among the objects of the present invention to provide an electrolytic condenser the filmiorming portion of whose anode does not protrude itself beyond the container.

A similar object of my invention is to provide an electrolytic device comprising a non filmforming container, serving as cathode, and a filmiorming anode, wholly contained within said cathode.

Another object is to provide a film-forming anode for an electrolytic device, wholly covered by and not emerging from the electrolyte solution.

A further object in connection with an electrolytic device of the character described is to provide non-film-forming supporting means for a film-forming anode, wholly confined within a non film-forming cathode container.

A further object of my invention in connection with an anode of an electrolytic device, installed as above described, is to provide lead-in connections, not integral with said anode and not exposed to contact with the electrolyte.

Another object in connection with an electro- 55 lytic device of the character described is to provide a film-forming anode which can be inserted and mounted as a whole within a non-film-forming container serving as cathode.

A further object of. this invention, in connection with the anode bottom lead-in of an electrolytic device, as described, is to provide liquid-tight sealing means which do not include any filmforming anode portion passing through the same.

Other more specific objects and advantages of the apparatus will appear as the nature of the improvements are better understood, the invention consisting substantially in the novel arrangement and correlation of instrumentalities herein fully described and illustrated in the accompanying drawings wherein similar reference characters are used to describe corresponding parts throughout the several views and then finally pointed out and specifically defined and indicated in the appended claims.

The disclosure made the basis of exemplifying the present inventive concept suggests a practical embodiment thereof, but the invention is not to be restricted to the exact details of this disclosure, and the latter therefore is to be understood from an illustrative, rather than a restrictive standpoint.

In the accompanying drawings- Fig. 1 is an elevation, partly in cross-section of a condenser, made according to the principles of the invention, the upper end of the anode being only indicated by dotted lines.

Fig. 2 is a horizontal cross section along the line 2-2 of Fig. 1.

Fig. 3 shows a modification of the cathode element of Fig. 1, the anode itself, which is assumed to be of identical construction as that of Fig. 1, being omitted. The supporting base of the anode, as shown, also presents some modifications.

Fig. i is a horizontal cross section along the line l l of Fig. 3.

Fig. 5 shows the principle of the invention, as applied to a spirally wound anode. The view is a cross-sectional elevation.

Fig. 6 is a horizontal cross section along the line of Fig. 5.

Fig. '7 shows the insulating top brace which holds the spirally wound anode in central alignment, drawn along ll-'l of Fig. 5.

Fig. 8 shows a fragmental and cross-sectional elevation of a modified form of a self-contained anode for an electrolytic condenser.

Fig. 9 is a horizontal cross section along the line Q-9 of Fig. 3.

Fig. 10 is a view, similar to Fig. 8, illustrating a further modification.

Fig. 11 is a cross section through the base support of this condenser anode, taken on line l l--l l of Fig. 10.

Fig. 12 shows an anode, similar to that of Fig. 10, the only modification being confined to the clamping screw, and

Fig. 13 is a cross section through the base of this anode, taken on line l ;ll3 of Fig. 12.

Fig. 14 is a modification of the anode base, shown in Fig. 1.

Fig. 15 is an elevation, partly in section, showing the principle of the invention, applied to another modified form of anode. The supporting base also shows some optional modification.

Fig. 16 is a horizontal cross section along the line ill-l6 of Fig. 15, illustrating the insulating disk.

Fig. 17 is an elevational cross section taken along the line l'll'l' of Fig. 15.

areas-is similar parts electrode or cathode of the condenser, is shaped from an aluminum tube by a recently developed extrusion process (see Figs. 1 and 5).

The top rim is formed with an annular contraction in the form of an inner bead or shoulder ll on which is seated a disk-like lid or cover it with a thin rubber diaphragm l3, expanded across the underside and around the rim, whereby it forms an air-tight packing around the lid. A pinhole i l, provided in a little extruded bulge la, in the center of the lid, serves as safety escape for the gas formed during electrolytic action, and when the condenser is put into service, the rubber diaphragm may be pricked open by a needle through said pinhole. The central part of the diaphragm, while the pinhole in it ordinarily closes up, will be stretched into the bulged portion of the lid by the gas pressure developed. opening the pinhole momentarily and letting the gas escape, automatically closing up again thereafter. The outer rim of the container is spun inwardly over the rubber diaphragm and the lid edge, forming an airand liquidtight closure.

The lower part of the container lil is contracted to form an annular bottom 35, ending in a cylindrical neck iii of smaller diameter. or nipple is threaded on the outside, and the container is mounted in an upright position by means of this neck or nipple onto an insulating chassis or panel board ll. A washer E81) and, a nut (Illa, between which a terminal clip ill can be clamped, complete the mounting of the condenser container onto the panel board.

This represents a typical form of the cathode container, but Fig. 3 shows an alternative form which under certain conditions,especially when there is no panel board provided on which the condenser can be mounted-is simpler and less expensive to manufacture. The container lfla in this case has a fiat bottom llla, which has only a small drilled hole Ell for a terminal screw 2! which also fast/ens the base support 22 for the anodeto be described later-to the inside of the flat bottom l5a. The condenser is held in a split clamp ring 23 which can also serve as a terminal connection for the cathode, as indi cated by the lead-in 24.

I shall now describe different forms of anodes which are possible in agreement with the principle of this invention as outlined in the premises. but it is to be understood that these forms are only given as illustrative examples and that many more modifications than are shown, are feasible and will come within the claimed scope of this invention, provided that they constitute a fi1mforming anode which as an integral piece does not project or extend beyond the confines of the cathode container, a conducting path which does not come in contact with the electrolyte, being provided in all cases to provide a terminal connection from the inner anode to the outer circuit.

In the form, illustrated in Figs. 1 and 2. which applies the principle of the inventive concept to the greatest advantage, the anode consists of a sheet of aluminum 25, folded or corrugated in Wave-form, the well rounded folds running in a This neck straight vertical direction, so that any gas bubbles formed by electrolytic dissociation can rise directly upwards without hindrance. If preferred the anode sheet may also be perforated in suitable manner (not shown) to facilitate a free circulation of the electrolyte. This anode sheet on which a uni-directional oxide film can be preformed before it is installed in the condenser, is mounted upon a separate base 26. This support, like the aforementioned base 22, is a short stub which can have different shapes and may even be made of different materials. It may have a cylindrical square or hexagonal cross section with a wide flange, 26a (or 22a respectively) on top.

On this. flange are secured by rivets or other suitable fastening means two rectangular brackets 21a and 21b, also of film-forming material (aluminum) to which the anode sheet ends are securely fastened. In Figs. 1 and 2 this is ac complished by clamping the last turns of the corrugated anode sheet over the upright legs of the brackets and riveting them together, or, as Figs. 8 to 13 indicate, these uprights 21a, b, or 21a", b" may be split and the corners of the anode film forced into the slots and, if desired, secured by additional means (pinching or extruding bulges across the clamped sheet, etc.).

If the stub itself is made of bare metal, it should be made also of film-forming material and in that case it forms a cooperative part of the anode, though likewise entirely contained in the interior of the outer cathode vessel. (See Fig. 1.) I

It is, however, also feasible to form this base of a non-conductive material, for instance, hard rubber, and in this case the base must have a metal core 23 which can be integral with the brackets, but wherever it makes contact with a non-filming metal, such connection must be well guarded against contact with the electrolyte solution, even against seepage, in order to prevent eddy currents and local action. See Fig. 14, which shows a plug 23- molded directly-into the hard rubber base 30 and forming an integral part of the fork shaped anode support 29.

The lead-in connection to the anode element is made by a screw 3| which is tapped from the underside of the panel board I! into the base 26 (or 30). A liquid-tight packing is provided by the soft rubber washer 32, between the anode base and the bottom. A rubber washer 33 is inserted between the outerhead of the screw and the face of the cylindrical cathode neck I6, and a fiber bushing 34 between them. A terminal clip 35 underneath the head of the screw provides for any connection with the outer circuit.

When the screw 3| is tightened, the anode base is pressed against the rubber washer 32 and the fiber bushing, and any seepage of the electrolyte toward the outside is effectively prevented.

The anode base, shown in Fig. 3 shows the rivets by which the brackets 21a, 2) are to be fastened, as integral parts of the main body, extruded in the manner of eyelet rivets 22b from the top flange; 22a. The rubber washer underneath the base is transformed into a rubber thimble 36, which gives a better protection against short-circuiting by accumulated sediment.

The anodeillustrated in Fig. 5 is a film-forming aluminum sheet 40, fastened with one end, flaglike, into longitudinal slot 4| of the anode pole 42 and wound spirally around it, yet with sufficient space between the windings. The extended top end of the pole has a shoulder 43 and is sprung through the central aperture of a nonconductive spacer disk 44, having also other apertures 45 for the free circulation of liquid and gases (see Fig. '7). The spirally wound sheet 40 may likewise be suitably perforated (not shown) for the same purpose, and other appurtenances, like a non-conductive annular screen between the cathode wall and the spiral anode may be provided, but as these features do not enter into the claims and are well known in the art, they are not further illustrated or described. The lower end of the anode pole, however, has a flanged seat 46 into which the outer terminal screw 3| is tapped. The terminal connections and the stufiing box for the same is analogous to that shown in Fig. 1.

Figs. 15 to 17 inclusive illustrate among other features another form of anode. This is, like the one shown in Fig. 1, a corrugated sheet of filmforming aluminum 60, but the folds run in a horizontal direction.

The comparatively narrow strip is folded over to form two equal branches, and the two lower elongated ends are firmly riveted-to a base stud 6|. In order to prevent accidental contact with the cathode container wall, the anode strip, at least at two points, is held in position by one spacer disk 62 respectively, which is best shown in Fig. 16. It is an originally circular nonconductive sheet (fiber, etc.) split in the middle at 63, so that it may be forked around two inner folds of the opposite branches of the corrugated anode strip. The periphery of the disk is furthermore provided with a few lunulate incisions 64 to facilitate circulation of the electrolyte.

While the anode, shown in Figs. 18 and 19, is similar to the one illustrated in Figs. 5 and 6', the cathode construction in this example, differs and is mainly shown to demonstrate that the principle of this invention is also applicable to electrolytic condensers with a non-conductive container, for example porcelain or hard rubber which completely surrounds both the anode and a separate cathode.

The container 65 consists of a cup-shaped body 65a with a lid 65!) screwed onto it. The outer cylindrical wall is provided with vertical ridges or channels 650 to facilitate heat radiation. The cathode 66 is a plain cylindrical non-filming sheet, seated upon the bottom of the container and advantageously provided with a plurality of perforations (not shown) to promote circulation of the electrolyte liquid. The cathode terminal 61, riveted to the top edge of the cathode, can in this case be carried through the lid, as shown, while the anode terminal may be brought through the bottom, similar to the arrangement shown in Fig. 3. The base 68 is integral with the nonconductive outer container, and the anode pole 69 of the anode spiral I0 is let into said base, resting with a broad shoulder ll upon the top of said base, a compressible rubber washer 12 inserted between them. When the terminal screw 13 which enters the pole from below, is tightened, a hermetical seal is effected.

It remains to describe a few modifications of the anode base, as depicted by Figs. 8 to 17.

According to Fig. 8, the supporting stud 41 is cup-shaped and perforated in the center to receive the head of a terminal screw 48, which is provided with a shouldered washer 49 of fiber or other insulating material, a terminal clip 54 and a nut 5! at the outer end to provide a liquidproof tightening of the anode stud against the bottom of the container. The space above the screw head is closed up by a plug 52 either of film-forming aluminum or wax or cement.

The construction shown in Fig. it) varies mainly from the last described, in that the screw head is covered by the anode seat which with a bottom extension flange is swedged around it, and in Fig. 12 the terminal screw 56 is reversed so that its slotted head is on the bottom, while it is screwed into a nut 55, resting within the swedged-over flange 55 of the anode seat.

Looking at the anode terminal connection, shown in Figs. 15 and 1'71, one observes that it comprises a stay bolt i l whose inner head is split and horizontally perforated, so that the shank lb of the base stud hi can be inserted and securely riveted to the head of the stay bolt. A fiber or rubber washer 76 is inserted underneath the broad shoulder Ella, so that a hermetical seal may be effected by tightening the terminal outer screw l ia.

A separate perforated cathode conduit 59 to which terminal connections can be made is permanently attached to the outer bottom side of the container, and the stay bolt is insulated therefrom by the non-conductive sleeve 58 and the fiber washer 5?.

it is thus seen that all the objects enumerated before, are attained in a simple, efficient and inexpensive way, and that at least one of the contributing causes of the deterioration and failings of electrolytic condensers and rectifiers is eliminated.

in accordance with the provisions of the patent statute, I have described my invention, but I desire it understood that it is not confined to the particular forms shown and described, the same being merely illustrative, and that the invention can be carried out in other ways without departing from the spirit of my invention, and therefore, I claim broadly the right to employ all equivalent instrumentalities coming within the scope of the appended claims, and by means of which, objects of my invention are attaind and new results accomplished, as it is obvious that the particular embodiments herein shown and described are only some of many that can be employed to attain these objects and accomplish these results.

Having now described my invention, what I claim and desire to secure by Letters Patent, is:

1. An electrolytic condenser, comprising a cathode in the form of a metallic vessel, having a araaers top and bottom wall, an electrolyte, an anode, made of film-forming metal, wholly immersed in the electrolyte liquid in said vessel and being entirely contained therewithin, a perforated cupshaped base, mounted on the bottom wall of the vessel, means to support the anode upon said base, said supporting means and said base being made also of film-forming material, a separate terminal screw bolt of non-filming metal for the anode, the head of said bolt being supported in the cup-shaped base, and covered against contact with the electrolyte, and the shank extending insulatingly through the bottom of the oathode toward the outside terminal connection for the anode and separate terminal connections for the cathode.

2. An electrolytic condenser, comprising a cathode in the form of a metallic vessel, having a top and bottom wall, an electrolyte, an anode,

made of film-forming metal, wholly immersed in the electrolyte liquid in said vessel and being entirely contained therewithin, a cup-shaped base, mounted on the bottom wall of the vessel, means to support the anode upon said base, said supporting means and said base being made also of film-forming material, a separate terminal screw bolt of non-filming metal for the anode, the head of said bolt being imbedded in the cupshaped base, and covered against contact with the electrolyte by said base, and the shank 6X- tending insulatingly through the bottom of the cathode toward the outside terminal connection for the anode and separate terminal connections for the cathode.

3. All electrolytic condenser, cathode in the form of a metallic vessel, having a top and bottom wall, an electrolyte, an anode, made of film-forming metal, wholly immersed in the electrolyte liquid in said vessel and being entirely contained therewithin, a cup-shaped base, mounted on the bottom wall of the vessel, means to support the anode upon said base, said supporting means and said base being made also of film-forming material, a Separate terminal screw bolt of non-filming metal for the anode, said screw bolt being inserted from the outside anode terminal insulatingly through the comprising a bottom of the cathode vessel and secured by a nut within the interior of the anode base in such a way that it is protected against contact with the electrolyte solution.

NATHAN SCHNULL. 

